Potassium channel openers and vascular smooth muscle relaxation.
Potassium channel openers comprise a diverse group of chemical agents which open plasma-lemmal K-channels. They show selectivity for smooth muscle, although K-channels in cardiac and skeletal muscle, neurones and the pancreatic beta-cell are also affected at relatively high concentrations. In addition, at least one endogenous K-channel opener of vascular origin--endothelium-derived hyperpolarizing factor--exists and in man plays a role in modulating blood vessel tone. The type of K-channel involved in the actions of both exogenous and endogenous K-channel openers is still uncertain, although a prime candidate in smooth muscle seems similar to the [ATPi]-modulated K-channel in the pancreatic beta-cell. This review focuses attention on the action of these agents in vascular smooth muscle and on the possible clinical exploitation of their powerful vasorelaxant properties.
Edwards
G
G
Department of Physiological Sciences, University of Manchester, UK.
Weston
A H
AH
D000818:Animals; D006801:Humans; D009130:Muscle, Smooth / Q000187:drug effects* / Q000502:physiology; D015221:Potassium Channels / Q000187:drug effects*
D015221:Potassium Channels